The family of the 4-year-old girl who was allegedly sexually assaulted by a teacher at Boone Elementary is now suing the Austin Independent School District.

The federal complaint claims AISD, AISD PD and one of its detectives has repeatedly failed to investigate accusations of sexual assault, and that has created a hostile environment that has denied female students "access to educational opportunities."

The complaint specifically names the detective assigned to the case, saying he routinely wraps up such investigations very quickly "without charges against perpetrators."

It describes the case in detail, claiming the detective was in the room after doctors performed surgery on the girl.

When the surgeon told them the girl was sexually assaulted, and that her injuries were not from a fall or straddle injury, the detective allegedly said, "You have no proof of that."

The case was first reported in February, but school police closed the investigation after the girl did not make an outcry during a police interview. 

Medical records showed she had signs of a traumatic assault, but as we first reported school police closed the case without pulling those medical reports.

AISD Chief of police Eric Mendez admits the mistake but says the medical professionals employed as part of the district's investigation team did review them.

The complaint was filed on Tuesday evening. A spokesman for AISD said the district has no comment because it has not yet been served with that paperwork.

Travis County District Attorney Margaret Moore told KVUE late last week that it appears as if this case was not a sexual assault.